The improved and relax semi-implicit compact schemes are presented, based on the second-order modified Dennis scheme for the convection-diffusion equations.

• 基于二阶修正Dennis格式 ；提出了采用时间相关法求解定常对流扩散方程的一种具有节省内存空间和提高定常解收敛速度的有理式型优化半隐和松驰半隐紧致格式 .